Capacitor component having external electrodes with reduced thickness

ABSTRACT

A capacitor component includes a body having a first surface and a second surface opposing each other and including a multilayer structure in which a plurality of dielectric layers are stacked and first and second internal electrodes are alternately disposed with respective dielectric layers interposed therebetween and exposed to the first surface and the second surface, respectively, first and second metal layers covering the first surface and the second surface and connected to the first and second internal electrodes, respectively, first and second ceramic layers covering the first and second metal layers, and first and second external electrodes covering the first and second ceramic layers and connected to the first and second metal layers to be electrically connected to the first and second internal electrodes, respectively.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation application of U.S. patentapplication Ser. No. 16/368,009, filed Mar. 28, 2019, which is adivisional patent application of U.S. patent application Ser. No.15/696,959, filed on Sep. 6, 2017, now U.S. Pat. No. 10,629,379, issuedApr. 21, 2020, which claims benefit of priority to Korean PatentApplication No. 10-2017-0000438 filed on Jan. 2, 2017, the disclosuresof which are incorporated herein by reference in their entireties.

TECHNICAL FIELD

The present disclosure relates to a capacitor component and a method ofmanufacturing the same.

BACKGROUND

A multilayer ceramic capacitor, a capacitor component, is a chip-typecondenser mounted on printed circuit boards of several electronicproducts such as an imaging apparatus, for example, a liquid crystaldisplay (LCD), a plasma display panel (PDP), or the like, a computer, asmartphone, a cellular phone, and the like, to serve to chargeelectricity therein or discharge electricity therefrom.

The multilayer ceramic capacitor (MLCC) may be used as a component ofvarious electronic apparatuses since it is relatively small, implementshigh capacitance, and is easily mounted. Recently, a multilayer ceramiccapacitor used in a mobile device, an automobile, or the like, isrequired to have a high degree of mechanical strength. For example, amultilayer ceramic capacitor used in a mobile device, an automobile, orthe like, should be able to endure environments in which repeatedexternal vibrations, impacts, harsh temperatures, humidity, and the likemay be encountered.

In the MLCC used in the related art, external electrodes are obtained byapplying and then sintering a paste. In the external electrodes obtainedas described above, thicknesses of outer regions of the externalelectrodes are relatively lower than those of central regions of theexternal electrodes. In a case in which the thicknesses of the externalelectrodes are non-uniform as described above, a decrease in a mountingdensity of the MLCC, deterioration of sealing characteristics of theexternal electrodes, a plating defect due to a blister, or the like, maybe caused.

SUMMARY

An aspect of the present disclosure may provide a capacitor component inwhich thicknesses of external electrodes may be reduced and sealingcharacteristics and moisture resistance reliability of the externalelectrodes may be improved. An aspect of the present disclosure may alsoprovide a method of manufacturing a capacitor component capable ofefficiently manufacturing the capacitor component.

According to an aspect of the present disclosure, a capacitor componentmay include a body having a first surface and a second surface opposingeach other and including a multilayer structure in which a plurality ofdielectric layers are stacked and first and second internal electrodesare alternately disposed with respective dielectric layers interposedtherebetween and exposed to the first surface and the second surface,respectively, first and second metal layers covering the first surfaceand the second surface and connected to the first and second internalelectrodes, respectively, first and second ceramic layers covering thefirst and second metal layers, respectively, and first and secondexternal electrodes covering the first and second ceramic layers andconnected to the first and second metal layers to be electricallyconnected to the first and second internal electrodes, respectively.

The first and second metal layers may cover the entire first surface andthe entire second surface of the body, respectively.

Each of the first and second metal layers may have a uniform thickness.

The first ceramic layer may cover the entire first metal layer, and thesecond ceramic layer may cover the entire second metal layer.

Areas of the first metal layer and the first ceramic layer, in relationto the first surface of the body, may be the same as each other, andareas of the second metal layer and the second ceramic layer, inrelation to the second surface of the body, may be the same as eachother.

The first and second external electrodes may have multilayer structures,respectively.

Each of the first and second external electrodes may include a firstlayer that is a sintered electrode and a second layer, which is aplating electrode, covering the first layer.

The capacitor component may further include a third metal layer disposedbetween the first ceramic layer and the first external electrode, and afourth metal layer disposed between the second ceramic layer and thesecond external electrode.

The first and second metal layers and the third and fourth metal layersmay be formed of the same material.

Areas of the first and third metal layers and the first ceramic layer,in relation to the first surface of the body, may be the same as oneanother, and areas of the second and fourth metal layers and the secondceramic layer, in relation to the second surface of the body, may be thesame as one another.

The first and second metal layers may include an Ni component.

The first and second ceramic layer may be formed of the same material asthat of the plurality of dielectric layers.

A weight ratio of organic material components in the first and secondceramic layers to the remaining material components in the first andsecond ceramic layer, may be greater than a weight ratio of organicmaterial components in the plurality of dielectric layers to theremaining material components in the plurality of dielectric layers.

The first and second external electrodes may extend to cover,respectively, third and fourth surfaces of the body opposing each otherwhile connecting the first and second surfaces to each other.

Portions of the first and second external electrodes covering the thirdsurface and the fourth surface, respectively, may be physicallyconnected to the metal layers.

According to another aspect of the present disclosure, a method ofmanufacturing a capacitor component may include: forming a body byalternately stacking a plurality of dielectric layers and first andsecond internal electrodes, forming first and second metal layers onsurfaces of the body on which the first and second internal electrodesare exposed, respectively, forming first and second ceramic layers tocover the first and second metal layers, respectively, and forming firstand second external electrodes to be connected to the first and secondmetal layers while covering the first and second ceramic layers,respectively.

The forming of the first and second metal layers may includetransferring the first and second metal layers to the body.

The forming of the first and second ceramic layers may includetransferring the first and second ceramic layers to the first and secondmetal layers, respectively.

The forming of the first and second metal layers and the first andsecond ceramic layers may include transferring a laminate of the firstmetal layer and the first ceramic layer to the body simultaneously, andtransferring a laminate of the second metal layer and the second ceramiclayer to the body simultaneously.

The method may further include simultaneously firing the body, the firstand second metal layers, and the first and second ceramic layers.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic perspective view illustrating a capacitorcomponent according to an exemplary embodiment in the presentdisclosure;

FIG. 2 is a schematic perspective view illustrating forms of a body, ametal layer, and a ceramic layer in the capacitor component of FIG. 1 ;

FIG. 3 is a cross-sectional view illustrating the capacitor component ofFIG. 1 ;

FIGS. 4 and 5 are, respectively, a perspective view illustrating a formof a body of a capacitor component according to a modified example and across-sectional view of the capacitor component; and

FIGS. 6 through 10 are views illustrating an example of a method ofmanufacturing a capacitor component according to an exemplary embodimentin the present disclosure.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view illustrating a capacitorcomponent according to an exemplary embodiment in the presentdisclosure. FIG. 2 is a schematic perspective view illustrating forms ofa body, a metal layer, and a ceramic layer in the capacitor component ofFIG. 1 . In addition, FIG. 3 is a cross-sectional view illustrating thecapacitor component of FIG. 1 .

Referring to FIGS. 1 through 3 , the capacitor component 100 accordingto the exemplary embodiment in the present disclosure may include a body101, first and second internal electrodes 111 and 112 included in thebody 101, metal layers 120, ceramic layers 130, and first and secondexternal electrodes 140 and 150 as main components. In the presentexemplary embodiment, as described below, a multilayer structure of themetal layers 120 and the ceramic layers 130 covering end surfaces of thebody 101 may be used, which is advantageous in miniaturization of thecapacitor component 100. In addition, sealing characteristics, moistureresistance reliability, and the like, may be improved due to themultilayer structure.

The body 101 may include a multilayer structure in which a plurality ofdielectric layers 113 are stacked, and the first and second internalelectrodes 111 and 112 alternately disposed with respective dielectriclayers 113 interposed therebetween. In this case, as in a formillustrated in FIG. 2 , the body 101 may have a hexahedral shape or ashape similar to a hexahedral shape, and include a first surface and asecond surface opposing each other. In this case, the first surface andthe second surface may correspond to left and right end surfaces of thebody 101 in FIG. 3 .

The dielectric layers 113 included in the body 101 may include adielectric material such as a ceramic material, or the like, known inthe related art, for example, a barium titanate (BaTiO₃)-based ceramicpowder, or the like. In this case, an example of the barium titanate(BaTiO₃) based ceramic powder may include (Ba_(1-x)Ca_(x))TiO₃,Ba(Ti_(1-y)Ca_(y))O₃, (Ba_(1-x)Ca_(x))(Ti_(1-y)Zr_(y))O₃, Ba(Ti_(1-y)Zr_(y))O₃, or the like, in which calcium (Ca), zirconium (Zr),or the like, is partially dissolved in BaTiO₃. However, an example ofthe barium titanate (BaTiO₃) based ceramic powder is not limitedthereto.

The body 101 may be divided into an active region forming capacitance,and cover regions positioned on upper and lower surfaces of the activeregion. In detail, in FIG. 1 , the active region may form thecapacitance by the first and second internal electrodes 111 and 112, andthe cover regions may be disposed on the upper and lower surfaces of theactive region. In this case, the cover regions may serve to preventdamage to the first and second internal electrodes 111 and 112 due tophysical or chemical stress, and may be formed of the same material asthat of the dielectric layers 113 of the active region and have the sameconfiguration as that of the dielectric layers 113 of the active regionexcept that they do not include the internal electrodes 111 and 112. Inthis case, the cover regions may be obtained together by stacking andthen sintering green sheets. The cover regions may be implemented in aform in which one or two or more green sheets are stacked on the upperand lower surfaces of the active region and are then sintered.

The first and second internal electrodes 111 and 112 may be alternatelydisposed to face each other with respective dielectric layers 113configuring the body interposed therebetween, and may be exposed to bothend portions of the body 101, respectively. Here, the first and secondinternal electrodes 111 and 112 may be electrically separated from eachother by respective dielectric layers 113 disposed therebetween. Amaterial forming each of the first and second internal electrodes 111and 112 is not particularly limited, but may be a conductive pasteformed of one or more of, for example, a noble metal material such aspalladium (Pd), a palladium-silver (Pd—Ag) alloy, or the like, nickel(Ni), and copper (Cu). A method of printing the conductive paste may bea screen printing method, a gravure printing method, or the like, but isnot limited thereto. In addition, thicknesses of the first and secondinternal electrodes 111 and 112 may be appropriately determineddepending on the purpose, or the like, and may be, for example, 0.1 to 5μm or 0.1 to 2.5 μm, but are not particularly limited thereto.

The metal layers 120 may cover the first surface and the second surfaceof the body 101, and may be in contact with the first and secondinternal electrodes 111 and 112. In this case, the metal layers 120 maycover the entirety of the first surface and the second surface of thebody 101 as in a form illustrated in FIG. 2 , and a surface of the metallayer 120 toward the body 101 may have the same area as that of thefirst surface of the body 101. In addition, the metal layers 120 mayhave uniform thicknesses in relation to the first surface and the secondsurface of the body 101. As an example that may obtain the metal layers120 having such a form, a process of transferring the metal layers 120to surfaces of the body 101 may be utilized.

In the related art, a process of applying and then sintering aconductive paste was used at the time of forming external electrodesconnected to the internal electrodes 111 and 112. Therefore,non-uniformity of thicknesses between central regions and outer regionsof the external electrodes occurred (thicknesses of the central regionswere greater than those of the outer regions). In the present exemplaryembodiment, the metal layers 120 having the uniform thicknesses areused, such that electrical characteristics may be uniform and moistureresistance reliability for moisture permeated from the outside of thecapacitor component 100 into the capacitor component 100 particularly atedge regions may be improved.

Meanwhile, the metal layer 120 may be formed of an appropriate metalamong metals having high electrical conductivity, and may include, forexample, an Ni component. In the present exemplary embodiment, the metallayers 120 may be provided in a form of a sintered electrode, and may besintered simultaneously with the body 101. In this case, the metal layer120, before being sintered, may be transferred to the body 101 in astate in which it includes metal particles, and an organic material suchas a binder, and the organic material, or the like, may be removed afterthe metal layer 120 is sintered.

The ceramic layers 130 may cover the metal layers 120, and may be formedof a ceramic material such as barium titanate, or the like. In thiscase, the ceramic layers 130 may include the same ceramic material asthe ceramic material included in the body 101, and may be formed of thesame material as that of the plurality of dielectric layers 113. As in aform illustrated in FIG. 2 , the ceramic layers 130 may cover theentirety of the metal layers 120. In this case, areas of the metallayers 120 and the ceramic layers 130 in relation to the first surfaceand the second surface of the body 101 may be the same as each other.The ceramic layers 130 may be formed in a manner of transferring theceramic layers 130 on the surfaces of the body 101 like the metal layers120, and may later be subjected to a sintering process. The ceramiclayers 130, before being sintered, need to have high adhesion for thepurpose of a transfer process. To this end, the ceramic layers 130before being sintered may include a relatively large weight ratio of anorganic material such as a binder, or the like to the remainingmaterials to form the ceramic layers 130. In this case, since some ofthe organic material may remain even after the ceramic layers 130 aresintered, the ceramic layers 130 may include a weight ratio of organicmaterial component to the remaining material component of the ceramiclayers 130 larger than a weight ratio of organic material component inthe plurality of dielectric layers 113 to the remaining materialcomponent in the plurality of dielectric layers 113.

As in the present exemplary embodiment, the ceramic layers 130 may beformed on outer surfaces of the body 101 to further improve sealingcharacteristics of the external electrodes, resulting in a significantreduction in permeation of moisture, a plating solution, or the like,from the outside into the body 101. In this case, the ceramic layers 130may be rapidly densified at the time of being sintered due to the metallayers 120 adjacent to the ceramic layers 130, and a structureappropriate for improving moisture resistance characteristics may thusbe effectively obtained.

The first and second external electrodes 140 and 150 may be formed onthe outer surfaces of the body 101, and may be electrically connected tothe first and second internal electrodes 111 and 112, respectively. Indetail, the first and second external electrodes 140 and 150 may coverthe ceramic layers 130, and may be in contact with the metal layers 120to thus be electrically connected to the first and second internalelectrodes 111 and 112, respectively.

The first and second external electrodes 140 and 150 may have multilayerstructures, respectively. For example, the first and second externalelectrodes 140 and 150 may include first layers 141 and 151 and secondlayers 142 and 152, respectively. Here, the first layers 141 and 151 maybe formed of sintered electrodes obtained by sintering a conductivepaste, and the second layers 142 and 152 may cover the first layers, andmay include one or more plating layers. In addition, the first andsecond external electrodes 140 and 150 may include other additionallayers, in addition to the first layers 141 and 151 and the secondlayers 142 and 152. For example, the first and second externalelectrodes 140 and 150 may include conductive resin electrodes disposedbetween the first layers 141 and 151 and the second layers 142 and 152to alleviate mechanical impacts, or the like.

In addition, as in a form illustrated in FIG. 3 , the first and secondexternal electrodes 140 and 150 may extend to cover, respectively, thirdand fourth surfaces of the body 101 opposing each other while connectingthe first and second surfaces of the body 101 to each other. Here, thethird surface and the fourth surface may correspond, respectively, to anupper surface and a lower surface of the body 101 in FIG. 3 . Regions ofthe first and second external electrodes 140 and 150 covering the thirdsurface and the fourth surface of the body 101, respectively, may bephysically connected to the metal layers 120.

FIGS. 4 and 5 are, respectively, a perspective view illustrating a formof a body of a capacitor component according to a modified example and across-sectional view of the capacitor component.

Referring to FIGS. 4 and 5 , the capacitor component according to themodified example may further include additional metal layers 121. Theadditional metal layers 121 may cover the ceramic layers 130. That is,the additional metal layers 121 may be disposed between the ceramiclayers 130 and the first and second external electrodes 140 and 150,respectively, to further improve moisture resistance reliability. Theadditional metal layer 121 may be formed of the same material as that ofthe metal layer 120, and may include, for example, an Ni component. Inaddition, as in a form illustrated in FIG. 4 , areas of the metal layers120, the ceramic layers 130, and the additional metal layers 121 inrelation to the first surface and the second surface of the body 101 maybe the same as one another.

In a case in which the additional metal layers 121 are formed, the firstlayers 141 and 151 of the first and second external electrodes 140 and150 may only be formed on the upper surface and the lower surface (thethird surface and the fourth surface) of the body 101, as in a formillustrated in FIG. 5 .

An example of a method of manufacturing the capacitor component havingthe structure described above will be described with reference to FIGS.6 to 10 . The structure of the capacitor component may be more clearlyunderstood through a description for the method of manufacturing thecapacitor component.

In a process of manufacturing the capacitor component, the metal layer120 may first be transferred to the surface of the body 101, as in aform illustrated in FIG. 6 . Here, the body 101 may be formed byalternately stacking the plurality of dielectric layers and the firstand second internal electrodes. For example, a manner of applying aconductive paste for forming an internal electrode to ceramic greensheets and stacking the ceramic green sheets to which the conductivepaste is applied may be used. The metal layers 120 may be formed on thesurfaces of the body 101 on which the first and second internalelectrodes are exposed. In a process of transferring the metal layers120, a metal layer 1200 having a sheet form may be prepared on asupporting stand 200, and the body 101 may be compressed to the metallayer 1200, such that a portion of the metal layer 1200 may be attachedto the surface of the body 101 and become the metal layer 120. The metallayer 120 transferred to the body 101 may be in a state before it issintered, and may include components such as a binder, an organicsolvent, and the like.

After the metal layer 120 is formed, the ceramic layer 130 covering themetal layer 120 may be formed as in a form illustrated in FIG. 7 , and atransfer process may be used, like that of the metal layer 120. That is,a ceramic layer 1300, before being sintered, may be disposed on thesupporting stand 200, and the body 101 may be compressed to the ceramiclayer 1300, such that a portion of the ceramic layer 1300 may beattached to a surface of the metal layer 120 and become the ceramiclayer 130. The ceramic layer 130, transferred to the body 101, may be ina state before being sintered, and may include components such as abinder, an organic solvent, and the like.

Meanwhile, processes of individually transferring the metal layer 120and the ceramic layer 130 are used in the present exemplary embodiment,but only one transfer process may also be used. That is, as in a formillustrated in FIG. 8 , after a metal layer 1200 and a ceramic layer1300 are stacked on the supporting stand 200, a multilayer structure ofthe metal layer 120 and the ceramic layer 130 may be obtained on thebody 101 by one transfer process.

In addition, FIG. 9 illustrates an example of a process of forming theadditional metal layer 121. An additional transfer process may beapplied in a state in which the metal layer 120 and a portion 130′ ofthe ceramic layer 130 are formed on the body 101. In this case, aceramic layer 1300 and a metal layer 1210 may be stacked on thesupporting stand 200 in a changed sequence. In this state, in a case inwhich a multilayer structure of another portion of the ceramic layer 130and the metal layer 121 is transferred to the body 101, a multilayerstructure may be obtained in a sequence of the metal layer 120, theceramic layer 130, and the additional metal layer 121 from the surfaceof the body 101.

An example of a method of forming the metal layer 120, the ceramic layer130, and the additional metal layer 121 on the body 101 has beendescribed hereinabove, and the same process may be applied to the othersurface of the body 101.

Then, the external electrode connected to the metal layer 120 whilecovering the ceramic layer 130 may be formed, and FIG. 10 illustrates aprocess of forming the first layer 141 of the external electrode. Asdescribed above, the first layer 141 may be obtained by dipping the body101 in a conductive paste 201. Then, the body 101, the metal layer 120,the ceramic layer 130, and the first layer 141 may be fired. Here, thebody 101, the metal layer 120, the ceramic layer 130, and the firstlayer 141 may be simultaneously fired.

As set forth above, according to the exemplary embodiments in thepresent disclosure, the capacitor component in which the thicknesses ofthe external electrodes may be reduced and the sealing characteristicsand the moisture resistance reliability of the external electrodes maybe improved may be obtained. In addition, the method of manufacturing acapacitor component capable of efficiently manufacturing the capacitorcomponent may be obtained.

While exemplary embodiments have been shown and described above, it willbe apparent to those skilled in the art that modifications andvariations could be made without departing from the scope of the presentinvention as defined by the appended claims.

What is claimed is:
 1. A capacitor component comprising: a body having afirst surface and a second surface opposing each other in a firstdirection, third and fourth surfaces opposing each other in a stackingdirection while respectively connecting the first and second surfaces toeach other, and fifth and sixth surfaces opposing each other in a seconddirection while respectively connecting the first to fourth surfaces,and including a multilayer structure in which a plurality of dielectriclayers are stacked in the stacking direction and first and secondinternal electrodes are alternately disposed with respective dielectriclayers interposed therebetween and extending from the first surface andthe second surface, respectively; first and second metal layers coveringthe first surface and the second surface and connected to the first andsecond internal electrodes, respectively; and first and second externalelectrodes covering the first and second metal layers, respectively,wherein the first metal layer is disposed only on the first surfaceamong the first, third and fourth surfaces, the second metal layer isdisposed only on the second surface among the second, third and fourthsurfaces, each of the first and second external electrodes extends tocover the third and fourth surfaces of the body, each of the first andsecond external electrodes includes a first layer that is a sinteredelectrode and a second layer covering the first layers and including aplurality of layers, on one of the third and fourth surfaces of thebody, a maximum dimension, in the stacking direction, of the secondlayer is greater than a maximum dimension, in the stacking direction, ofthe first layer, and the first layer is in contact with end portions ofthe first metal layer which oppose each other in the stacking directionand end portions of the first metal layer which oppose each other in thesecond direction.
 2. The capacitor component of claim 1, wherein thesecond layer of each of the first and second external electrodesincludes a plurality of plating layers.
 3. The capacitor component ofclaim 1, wherein each of the first and second metal layers has a uniformthickness.
 4. The capacitor component of claim 1, wherein the firstmetal layer extends from, but does not cover the third surface or thefourth surface, and the second metal layer extends from, but does notcover the third surface or the fourth surface.
 5. A capacitor componentcomprising: a body having a first surface and a second surface opposingeach other in a first direction, third and fourth surfaces opposing eachother in a stacking direction while respectively connecting the firstand second surfaces to each other, and fifth and sixth surfaces opposingeach other in a second direction while respectively connecting the firstto fourth surfaces, and including a multilayer structure in which aplurality of dielectric layers are stacked in the stacking direction andfirst and second internal electrodes are alternately disposed withrespective dielectric layers interposed therebetween and extending fromthe first surface and the second surface, respectively; first and secondmetal layers covering the first surface and the second surface andconnected to the first and second internal electrodes, respectively;third and fourth metal layers each including Ni and respectivelydisposed on the first and second metal layers, respectively; a firstsintered electrode connecting the first metal layer and the third metallayer to each other; and a second sintered electrode connecting thesecond metal layer and the fourth metal layer to each other; and firstand second plating layers covering the third and fourth metal layers,respectively, wherein the first metal layer is disposed only on thefirst surface among the first, third and fourth surfaces, the secondmetal layer is disposed only on the second surface among the second,third and fourth surfaces, each of the first and second plating layersextends to cover the third and fourth surfaces of the body, on one ofthe third and fourth surfaces of the body, a maximum dimension, in thestacking direction, of the first plating layer is greater than a maximumdimension, in the stacking direction, of the first sintered electrode,and the first sintered electrode is in contact with end portions of thefirst metal layer which oppose each other in the stacking direction andend portions of the first metal layer which oppose each other in thesecond direction.
 6. The capacitor component of claim 5, wherein each ofthe first and second metal layers has a uniform thickness.
 7. Thecapacitor component of claim 5, wherein the first and second metallayers are in contact with the first and second internal electrodes,respectively.
 8. The capacitor component of claim 5, wherein the firstsintered electrode is in contact with the third metal layer, and thesecond sintered electrode is in contact with each of the second metallayer and the fourth metal layer.
 9. The capacitor component of claim 5,wherein the first and second plating layers are in contact with thethird and fourth metal layers, respectively.
 10. The capacitor componentof claim 5, wherein the first metal layer extends from, but does notcover the third surface or the fourth surface, and the second metallayer extends from, but does not cover the third surface or the fourthsurface.